Glyceryl monomercaptan composition and method of cold waving



United States mm to Sales Afiliates, Inc., New York, N.Y., a corpora tion of New York No Drawing, Applnafion December a, 1951 Serial- No. 259,732 Claims. 01.132-7) This application is a continuation-impart of my copending application, Ser. No. 398,235, filed June 16, 1941, now Patent No. 2,577,710.

This invention relates generally to the art of permanently altering the physical form or shape of hair, and, more particularly, to the art of permanently waving hair.

It is known that the physical form or shape of hair can be permanently altered without injury to the hair structure by utilizing three forces, namely, a mechanical force, a chemical or softening force, and a fixing or setting force. More particularly, in permanent Waving the mechanical force is setup by Winding the hair in curls as on mandrels. A chemical medium is then (or previously) applied to create the chemical or softening force adapted to place the wound tresses in condition to be permanently molded and altered to their new form as determined by the Winding. Finally, means are utilized to fix the wound tress'es in their new form, which latter means may consist of an application of heat, generated electrically, chemically or in any other way followed by cooling or a second chemically reactive force to neutralize the chemical waving medium.

The present invention is concerned with the chemical medium which provides the chemical or softening force above referred to, being identified hereinafter for descriptive purposes only as the waving solution, and comprising an aqueous solution containing the waving agent or agents.

Heretofore, the practice has been to use a waving agent for such solutions which is an alkaline material, for example, borax, various carbonates and phosphates of alkaline materials, ammonia and ammonium salts, such as the carbonates. Furthermore, soluble sulfites of alkalies and ammonia have been utilized for the waving agent, and sulfides have also been provided for this purpose.

However, with respect to the sulfites and to all other heretofore utilized waving agents excepting sulfides, relatively high concentrations are'n'ecessary in order to obtain any satisfactory permanent wave in the hair. Especially with fine hair, there is diflieuuy in providing a suitable waving solution for obtaining an altered form or shape for the hair which can be termed permanent.

I have found that there isa limiting concentration of these materials above which either hair destruction or injury occurs with less satisfactory wave. It is probably this upward limiting effect on concentration of these wavin'g agents that make it" impossible to obtain satisfactory results in a short time where the hair is set by a chemical force, for the solution containing these waving agents must be left in contact with the hair for periods ranging from four to twenty-four hours before a satisfactory wave may be obtained.

The sulfides do not require as long a time nor need quite as great a concentration as the sulfites anda satisfactory solution may be made therefrom for most types of hair and even fine hair undersome conditions, but many disadvantages appear when using sulfides, the first of which is the characteristic odor of rotten eggs possessed by such sulfides resulting from generation and liberation of free hydrogen sulfide by hydrolysis. All attempts to mask this odor result in failure and the use of heavy perfumes only serve to minimize the objectionable odor. Secondly, these sulfides have a tendency to cause tarnish ing and blackening on metal, particularly jewelry, silver- Ware, and the like, which is a further objection to their use in the waving lotion. Furthermore, the disgusting odor which accompanies the use of such hydrogen sulfide salts is toxic to breathe and although normally the amount of hydrogen sulfide produced thereby is not dangerous, when in a confined booth or room such as a beauty shop cubicle often used in hair waving establishments, the concentration of the gas may become so high as to s eri ously alfect both operator and patron, unless expensive ventilating equipment is installed and maintained to remove this gas.

Thus, it will be seen that, while these sulfides are satisfactory in use in waving solutions from the point of view of performance or results in the finished permanent wave, they are wholly unsatisfactory because of the combined effect of toxicity, nauseating odor, and metallic coating effect.

More specifically, one of the best waving agents known for use when carrying out a permanent change of form or shape of the hair is ammonium hydrogen sulfide; but, despite its relatively greater waving power, the use thereof is limited by liberation of hydrogen sulfide gas, together with ammonia gas. These evolved gases make this compound very objectionable and perhaps dangerous, unless special precautions to remove the vapors, for instance, by suction ventilators, are taken. v

Another objection to use of ammonium hydrogen sultide and other sulfides is that the hair tends to retain the sulfide in spite of repeated rinsings even when using a chemical setting solution. The result is a mal-odor to the hair, particularly on each re-wetting; More important, however, is the fact that this retention by the hair of the sulfide aifords a continuous relaxing elfect on the permanent wave with the result that the wave becomes less tight with each re-Wetting.

It is the general objective of this invention to provide an agent for use in altering the permanent form or shape of hair which will be similar in its efiect to that of the sulfides referred to above and yet will not possess the great disadvantages mentioned;

It is a further object of this invention to provide a lotion for the permanent waving of hair containing an entirely novel ingredient as the Waving agent which will give the solution a wide range of adaptability for permanent waving of any type or texture of hair.

It is a further object of this invention to provide a non-odorous, non-toxic hair waving solution adapted to more rapidly and more successfully place hair in a condition to be altered in form or shape permanently, ir-' respective of whether cooling subsequent to heating or chemical means is used after applying the waving solution in order to fix the hair in its new configuration.

It is a' further object of this invention to provide a waving solution suitable for that type of permanent wa'ving of hair which utilizes a chemical action for the fixing of the hair in its wound form, such waving solution containing a waving agent as powerful, rapid and satisfactory as ammonium hydrogen sulfide, but free from the limitations of ammonium hydrogen sulfide, particularly the bad odor and toxicity.

It is a further object of this invention to provide a waving solution powerful enough to wave hair without the need of added heat and which can be neutralized or completely removed by water alone; or, in other words, the wave can be fixed in the hair by washing out the Waving agent with water alone.

By this invention there is provided an agent for use in the permanent reforming of hair which is fast in action, satisfactory in use for all types of hair and yet is free from objectionable odors or toxicity or the like.

I have discovered that I can obtain these objects by providing as a waving agent a mercaptan, or a mixture of mercaptans, whether the fixing of the new form for the hair be by cooling subsequent to heating, or by using chemical rinses or by any other method, and, further, that an effective waving solution can be obtained by proper formulation including a mercaptan in Water. The mercaptans are represented by the formula R--SH where R is an organic group such as the ethyl group in H H Ethylmercaptan HC-O-SH or the benzyl group in H Benzyl mercaptan g-SH Such simple mercaptans will function adequately as waving agents, but they still have the disadvantage of sulfides, such as ammonium hydrogen sulfide as far as bad odor is concerned.

I have discovered that bad odor, and other disadvantages can be entirely obviated by having the molecule contain other groups which are carefully selected, as hereinafter set forth, to give the optimum desired results. For instance, the mercaptan molecule may contain polar groups, which in turn may be either acidic or alkaline groups. Examples of compounds and groups of compounds belonging under the general heading of polar acidic substituted mercaptans are: mercaptans containing the carboxylic groups, as, for example, the simple mercapto-alkanoic acid, mercapto-acetic acid (Thioglycollic), mercaptans containing sulfonic groups, as, for example, mercapto-ethyl sulfonic. Other acidic groups are nitro, chloro, or other halogenated groups, sulfonic, sulfate. It is to be noted that any homologues could be used and that cyclic, or benzenoid groups may be ineluded-also derivatives of these compounds, such as salts, esters, amides, and the like. Examples of polar alkaline substituted mercaptans are: Mercaptan contain ing amino groups, which may be primary, as, for example, B-amino ethyl mercaptan, or, secondary, as, for example, B-mercapto-ethyl-methyl amine or tertiary, as. for example, fi-mercapto ethyl di-methyl amine. Other alkaline groups are imines and nitrogen heterocyclic compounds. It is to be noted that any homologues could be used and that cyclic, or benzenoid groups may be included-also derivatives of these compounds, such as salts, nitrogen derivatives, amides, and the like.

On the other hand, the molecule may contain nonpolar groups. An example of a mercaptan containing the non-polar hydroxyl group is the simple mercaptocarbinol compound, B-mercapto-ethyl alcohol. An eX- ample of mercaptans containing non-polar aldehyde groups is the simple mercapto-carbinol, mercapto acetaldehyde. An example of mercaptan containing nonpolar ketone groups is the simple mercapto-carbonyl, mercapto-di-methyl ketone. An example of mercaptan containing ester groups is the simple mercapto-ester, mercapto ethyl acetate. As an example of mercaptan containing other groups is the simple mercapto-ether, B-mercapto di ethyl ether. Homologues, cyclic or benzenoid and other derivatives of these compounds could be used.

Many other compounds could be listed such as the mercaptan containing more than one substituted group such as, for example, 3 amino-2 hydroxy propyl mercaptan.

Many other mercaptan compounds could be included under the groups above and the following lists are given to show the wide variety of mercaptans which may be used and to show that mercaptans having poly mercaptoand poly substituted groups may be used: (1) Thioglycerol, mono-, di-, or polythio-polyhydric alcohols, e.g., trithio hexitols, monoand polythio-polyoxyethylene glycols, (e.g., tetra glycol dimercaptan); (2) mercaptoethylhydroxy ethylamine, trio-mercapto-ethyl amine; (3) mono-, di-, and polythio-polyhydroxyacids; (4) mercapto diand polycarboxylic acids, mono-, diand trithio mucic acids, mon0-, di-mercapto succinic acid, thiocitric acid, mercaptoamino acids; (5) alpha mercapto-methyl furane, thiophene, pyrrole, pyrimidine, thiofufuralcohol; (6) mercapto alkyl pseudo thioureas; (7) mercaptoalkylureas and thioureas; (8) mercaptoethyl urethane, mercaptoethylacetamide, mercapto ethyl guanidine, mercaptoalkyl betaines and taurines.

I have discovered that all of the materials mentioned above function satisfactorily as hair waving agents when used in solutions. The concentration is usually less than 15% in terms of weight per volume. I have found that the mercaptans are especially effective when the pH is in the alkaline range from above 7.0 to below 10.0, the preferred pH being about 9.2.

I have found that all alkaline materials are satisfactory for adjusting these pH, but that particularly elfee tive with less hair destructive efiect are bases having a dissociation constant less than 5 10- and preferably about 10- In the cold waving process also I have found the volatile bases, such as ammonia, methylamine, and ethylamine are to be preferred with the mercaptans, since at the same pH value and mercaptan concentration solutions containing these volatile bases give tighter waves. Ammonia, therefore, is particularly to be preferred with the mercaptans since its ionization constant is satisfactory, its odor blends pleasantly with the mercaptans and it has a relatively nonirritating action in the desired pH range of above 7.0 to below 10.0.

This pH range is particularly critical when the waving agent is used for that type of waving employing a chemical setting agent, as in the so-called cold waving method, since in that system the necessary requirement of speed without hair destruction demands a high concentration of the waving agent in the waving solution. If the pH value is not high enough slow waving action will result and if too high the hair will be destroyed or badly damaged. While with sulfite a shorter waving time may require a pH of 10 or above, with these more powerful waving agents, the use of pHs higher than 9.5 must be watched very carefully for with pH of 10 or above, hair destruction or injury may occur before a satisfactory wave is obtained.

When my preferred bases are used, particularly those having a dissociation constant of about 10- and specifically ammonia, I have found that by the incorporation of certain salt materials the pH of the solution can usefully be lower and even below my preferred pH range of from about pH 9.2 to pH 9.5, and particularly below about pH 9.2, without affecting the speed of waving. I can do this in two ways.

The first way is to use a salt of the base where the acid of the salt has the same dissociation constant as the base. For example, ammonium acetate can be added to a solution of a mercaptan whose pH has been adjusted with ammonia to the desired alkaline pH. The amount of the ammonium acetate added will determine the extent to which the pH of the solution will be lowered, while essentially retaining the waving efiiciency or speed of the pH level to which it was adjusted before the addition of such salt.

The second way, which is preferred and much better, is to add a salt of the base wherein the acid has a dissociation constant less than the base. When this is done, the amount of the base alone does not'need to be as great since the stronger base of the salt will give to the solution an alkaline reaction. Ammonium carbonate is an example of a salt that can be used in this way.

It is to be noted that organic sulfides and are not effective waving agents.

I have discovered that whereas all the mercaptans function very effectively in permanent waving where the final set is accomplished by heating and then cooling, when used in the so-called cold waving method requiriug a chemical setting solution, unusual and startling differences from the prior art become apparent.

Furthermore, I have found that mercaptans containing polar groups are diflicult to remove from the hair and whenever the hair becomes damp, for instance, in bathing, shampooing, or at sports such as skiing, the residual odor tends to offend. This is most observable with mercaptans containing polar alkaline groups such as fi-amino ethyl mercaptan.

This odor effect is thus of tremendous importance, not only during the processing of the wave, but for a long time after the wave has been given. As stated above, the bad odor and other disadvantages of the simple mercaptans can be obviated by having the organic group R of the mercaptan molecule contain either polar or non-polar groups. By the term vapor-pressure-depressing substituent in the organic group R of the mercaptan formula RSH, is meant a substituted mercaptan which contains in its organic group R either a polar (ionizing) group or a non-polar (non-ionizing) group of the type above described. I have found that whereas certain groups such as polar groups tend to reduce the vapor pressure of the mercaptan and thus make the resulting mercaptan less objectionable, nevertheless the malodor, although much fainter, tends to persist. I have discovered, however, that while the nonpolar groups may be less effective in reducing the vapor pressure yet they change the resulting odor by' the sweetening action of their groups. For example, to illustrate the sweetening power of the hydroxyl group, thioglycerol is much sweeter than thiopropylene glycol which in turn is sweeter than the propyl mercaptan. Also, other nonpolar groups, such as ethers, aldehydes, ketones and esters are effective, as is illustrated by the effect of the ether linkage of the following related compounds. Increasingly pleasant to smell are diglycol di-mercaptan, triglycol dimercaptan, tetraglycol dimercaptan.

I have also discovered that as the molecular Weight increases, the mercaptan becomes less effective as a waving agent, particularly if the increase is due to a polar acid group. For example, ,B-amino ethyl mercaptan (molecular weight 77) is far more efiicient as a waving agent than cysteine (molecular Weight 121) which is molecularly heavier and contains the polar carboxyl group in addition to the polar amino group.

I have discovered that by far the best waving agents within the scope and spirit of this invention, from every standpoint, are the mercaptans containing non-polar groups, and particularly water-solubilizing groups, such as the hydroxy and ether groups thereof. For example, on a basis of odor, waving strength, and toxicity, these compounds in cold waving particularly, are far more desirable and effective than ammonium hydrogen sulfide, which has heretofore been utilized particularly for cold waving. Actually, not only do these non-polar mercaptans give better waving results and lack bad odor but also they are easier to remove from the hair and can be completely removed by shampooing or by thoroughly rinsing with water, no mal-odor being detected on the hair. More important, is that their easy removal allows practically no retention by the hair to effect a relaxation or loosening of the permanent wave with each succeeding wetting of the hair. 1

This very important feature of not losing its curl, once the hair is waved, and the imparting of an excellent elasticity to the curl and a fine lustrous natural gloss, result in a more natural appearance than has been possible disulfides with prior hair waving treatments. Particularly effective are the mercaptans containing more than one water-solubilizing group as, for example, the polyhydroxy mercaptan, e.g., thin-glycerol (glyceryl monomercaptan). This substances great value, on an equivalent SH basis is shown by the fact that it is several times as powerful in waving value as ammonium hydrogen sulfide.

As illustrations of waving solutions using the new waving agents according to this invention, the following spe- The waving solution in any of the above examples may be utilized for effecting a cold wave by soaking the hair therein and applying thereafter a rinse, say, of sodium hypochlorite or other suitable rinse such as hydrogen peroxide, tartaric acid or the like, I have found that it is desirable to remove as much of the solution of the waving agent as possible by first rinsing with water. I have discovered that with mercaptans containing water-solubilizing non-polar groups, such as glyceryl monomercaptan, so complete is the removal by water alone that ex cellent non-relaxing waves can be obtained without the need for additional fixing or setting rinses.

In the examples given above the treatments resulted in satisfactory curls of medium tightness. For Example 1, however, the wave produced was not as strong as that given with the waving solutions of Examples 2 and 3.

The hair treated with the solution of Example 3, which needed no ammonium hydroxide added, did, however, tend to retain an odor noticeable upon wetting the hair while with the solution of Example 2 not a trace of bad odor was present even when the waved hair was re-wetted. For more effective washing out of the mercapto-containing amines from the hair, it is possible to have additional groups such as hydroxyl present. Particularly effective as such a compound is Z-hydroxy 3-amino propyl mercaptan.

Thus it is seen that mercaptans containing polar and non-polar groups may be used. It has been brought out hereinbefore that either polar or non-polar groups are Within the spirit and scope of this invention. Polar groups differ from non-polar in that in water solution they may ionize.

If any of the above examples are used for waving where heat is employed, the concentration of the waving agent may be materially decreased, approximately to one-third or one-fifth of the concentration given in the examples.

Thus, for waving where heat is employed, the concentrations of the waving agents given in the above examples, so decreased, would be:

EXAMPLE 1 Polar typeacidic Mercapto-acetic-about 2 gms. to 3.3. gms.

EXAMPLE 2 Non-polar type Glyceryl monomercaptan-about 1 gm. to 1.66 gms.

EXAMPLE 3 Polar typebasic Mercapto ethylamine-about 1 gm. to 1.66 gms.

in considering this invention, it must also be borne in mind that a purpose is to provide a waving agent for use in a solution, the concentration of the waving agent being much lower than heretofore effective commensurate with the desired effect of waving the hair.

As a comparison of the reduction of concentration of the waving ingredient provided by the instant invention as against that of one of the standard waving agents used in this art, namely, sodium sulfite, I have found that the same wave under the same conditions of procedure can be given with about one fifth of the concentration of our new waving agent, e.g., a solution of 2% of mercapto ethylamine will give the same effect as 15% of sodium sulfite. Thus, by the instant invention, I can use the same time of operation but greatly reduce the concentration of the waving ingredient. Alternately, I can shorten the time of waving by using a stronger concentration but still below the concentrations heretofore used, for instance the sodium sulfite above mentioned. I, therefore, provide a complete control of the waving process by the waving agent.

Utilizing the waving solution of any of the examples, the following procedure, or one similar thereto, may be employed in giving a permanent wave: The head of hair is blocked off into sections and each of the sectioned strands is then well soaked in the waving solution. Thereafter, each section of hair is wound on a mandrel to the form desired and heat is then applied, as by a chemical heating pad arranged over the wound section or by an electrical heating unit, the temperature being raised to about 212 F., and the hair, upon cooling, sets into its new configuration.

In giving a cold wave, procedures similar to the following, which may be variously modified, may be used: The head of hair is again sectioned bit into strands which are preferably wound on mandrels, the waving solution being applied before or after winding by soaking the hair in any desired manner. After a suitable lapse of time for the reaction, the hair is water rinsed, and then a chemical rinse such as chlorine water may be applied which removes the last trace of the waving agent and thus assures the fixing of the hair in its new configuration, whereafter the hair will have a permanent wave. With an easily rinsable waving agent, such as glyceryl mono-mercaptan, this after rinse treatment is not necessary if proper water rinsing is employed.

I have found that in order to reduce the time of waving by this chemical method, i.e. without heat, to a figure comparable to the time of Waving by heat it is necessary to increase the concentration of mercaptans in the waving solution about three to five times.

Thus, the concentrations of mercaptans in the above examples, when so increased from the concentrations suitable for waving with heat, would be as follows:

EXAMPLE 1 Polar typeacidic Mercapto-acetio-about 6 gms. to 10 gms.

EXAMPLE 2 Non-polar type Glyceryl monomercaptau-about 3 gms. to 5 gms. to 8.3

gms.

EXAMPLE 3 Polar typebasic Mercapto ethylarnine-about 3 gms. to 5 gms. to 8.3 gms. Thus, it is possible to so select the concentration of my novel waving agent in the waving solution that the desired time of actual treatment becomes feasible, rang &

ing from a low concentration with longer time of application as is desired in some methods of cold waving, or a low concentration in continuous intimate contact with shorter time of application, or a low concentration with shorter time using heat, to higher concentrations with decrease in timewhether the fixation is by chemical, or by cooling subsequent to heating. Since the time of waving is greater with lower concentrations and less with higher concentrations of mercaptans and since, as described above, the time of waving is greater with a lower pH value and less with a higher pH value, it follows that the concentration of the mercaptan and the pH of the solution can be adjusted within the ranges given above to obtain a permanent change in the configuration of human hair during a given time of application without damage to the hair structure by having the concentration of mercaptan in the higher portion of the concentration range for a lower pH and having the concentration of mercaptan in the lower portion of said concentration range for a higher pH. But I do not under any conditions use concentrations higher than heretofore used. On the contrary, comparing the time-concentration factors of my novel waving agent with waving agents of the prior art for equivalent purposes, it will be found that under all analogous conditions I provide a distinct reduction in concentration while attaining optimum results in the final waving.

Referring now to that feature of the invention relating to the use of certain types of salt materials for reducing the pH value of a solution while maintaining substantially equivalent waving speeds to those produced by the solution at its original pH, the following specific examples of such features of the invention are given:

Solution A.An aqueous solution containing 5% of mercapto acetic acid and sufiicient ammonia, from the addition of ammonium hydroxide to give a pH of 9.2.

Solution A1.--The same as Solution A but containing 5% of thioglycerol (glyceryl mono mercaptan) instead of mercapto acetic acid.

Solution B.--The solution formed by the addition of 6% of ammonium acetate to Solution A, the pH thereof being thereby reduced to 9.0.

Solution BJ.The addition of 6% ammonium acetate to. Solution A1, whereby the pH is reduced to 9.0.

Solution C.A base aqueous solution is formed containing 5% of mercapto acetic acid and sufiicient ammonia by the addition of ammonium hydroxide to provide a pH of 8.6; by the addition of 6% of ammonium carbonate the pH of this solution is reduced to 8.55.

Solution C1.-The same as Solution C with 5% of thioglycerol in place of the mercapto acetic acid.

All of the solutions given above, that is, Solution A to Solution Cl inclusive, have approximately the same speed ofwaving, although Solutions B and B1 are slightly inferior to Solutions A and Al, C and C1 in that respect.

By the addition of ammonium carbonate, the waving speed of solutions like A and A1 (which are at my preferred pH value 9.2) can be increased; or by application to the hair for the same length of time, such solutions containing additions of ammonium carbonate will produce tighter curls. For example, the addition of 1% of ammonium carbonate to Solution A1 gives a tighter curl than said Solution A1 with the same time of hair treatment; the addition of 3% of ammonium carbonate to Solution Al gives a still tighter curl under the same conditions of treatment; while the addition of 6% ammonium carbonate gives an even tighter curl. However, starting with the original pH of 9.2, the effect of additions of such progressively greater amounts of ammonium carbonate is progressively to reduce the pH from that of the original 9.2 of the starting Solution Al.

Thus it is' apparent that when a waving solution contains. a salt formed from one of my preferred bases and anacid weaker than said base, the addition of such salt aeeasas may facilitate the obtaining of a faster rate of waving or fighter curls for the same length of treatment time compared. with a solution of the same or even higher PH and the same mercaptan con entration withou s c salt. Also, by the selection of the acid which forms the salt, particularly with respect to the dissociation constant of such acid, it is possible within certain limits to regulate the pH of the waving solution while obtaining such equivalent or better results. For example, ammonium carbonate formed from ammonia, which in aqueous solution has a dissociation constant of about 10- and carbonic acid whose first hydrogen has a dissociation constant of about 10- and whose second hydrogen has a dissociation constant of about 10" gives a pH about pH 8.3; whereas boric acid whose first hydrogen has only a dissociation constant of about 10- gives a salt whose solution gives a higher pH value than ammonium carbonate. Thus by the addition of equivalent amounts of ammonium carbonate and ammonium borate, the pH of the same starting solution of ammonium hydroxide and mercaptan (pH 9.2) will be reduced more by the ammonium carbonate than by the ammonium borate. However, both salts are good examples of the type which I prefer to use for the desired effect with my preferred base, ammonium hydroxide.

Hence, to summarize, I have found to work in the pH region below my preferred pH of about pH 9.2, while obtaining substantially equivalent times of treatment, that it is advantageous to use a salt formed from a base having a dissociation constant less than 5 l0 preferably about 10- preferably volatile, and most preferably ammonia, and from an acid having a dissociation constant less than the base, preferably less than about l* preferably volatile, and most preferably carbonic acid.

Other examples of the use of bases of the preferred class with acids of the preferred class to form salts having desired characteristics are exemplified by the following:

Ethanolamine carbonate, which is an example of a salt formed from a non-volatile base having a dissociation constant about with a volatile acid having a dissociation constant less than 10"' Ethanolamine borate is an example using the same base with a non-volatile acid having a dissociation constant less than 10- Similarly boric acid may be used with other bases having the preferred dissociation constant of about 10'' such as monoethanolamine, ammonia, methylamine and ethylamine. Obviously also carbonic acid may be employed with any of such bases to form a desirable salt in this connection. It will be understood generally that the base forming the salt is to be the same base as that used to adjust the pH of the starting solution. Thus if the pH of the starting solution of thioglycolic acid is adjusted to 9.2 with ammonium hydroxide, ammonium carbonate is preferably used, while if adjusted with monoethanolamine, monoethanolamine carbonate is preferably used as the salt.

There is, of course, a maximum amount of these salts that can be used and this is not alone due to the solubility. I have found that beyond a certain amount of the salt there will be no increase in Waving effect and actually a decrease if very large quantities are used. I prefer to use less than 12% of ammonium carbonate and preferably about 4 to 8% and with concentration of mercaptans of an equivalent concentration of that of a 5% thioglycerol solution, I prefer to use a salt like ammonium carbonate at about 5% or in an equivalent concentration if another salt is used. I have also found that the pH of waving solutions containing these salts should preferably be not less than pH 8 and not more than pH 9.2.

While throughout this specification I have specifically mentioned the waving of hair, I do not wish to limit myself thereto, since by this invention it is possible to Perm nt y ter o eform the orm, shape nfisuration of the hair as desired, Thus my invention contemplates also the reverse of Waving, such as de-kinking, removal of curls or waves, imparting of creases and the like. Furthermore, it is not my intention to limit this invention or the term hair as used herein to treatment of human hair, but rather to include the treatment of any form of fiber structure which contains keratin. The waving solution according to this invention may be ap plied to the hair at any desired time, either before or after winding or otherwise mechanically placing the hair in its reformed desired shape or form and by any desired means, such as soaking, spraying, continuous circulation or the like and the claims are to be so construed. Furthermore, while I have described examples of our invention and have outlined advantages thereof over the prior art, I do not wish to limit myself to the exact materials or proportions given hereinbefore since a variety of like or similar materials may be used in lieu of those specified and the proportions thereof may be widely varied without departing from the spirit of my invention or the intended scope of the appended claims.

What I claim is:

1. A permanent waving composition comprising glyceryl monomercaptan in a solution containing a base having a dissociation constant less than 10*, and a salt of said base, said salt being for-med from an acid having a dissociation constant less than that of said base, said solution having a pH higher than pH 7 and not higher than pH 9.5, the concentration of said mercaptan in terms of weight per volume ranging between about 1% and about 10%.

2. A composition as specified in claim 1 wherein the base is ammonia.

3. A composition as specified in claim 1 wherein the base is ammonia and the salt is ammonium carbonate.

4. A composition as specified in claim 1 wherein the base has a dissociation constant of about 10* and the salt is formed from an acid having a dissociation constant less than 10- 5. A composition as specified in claim 1 wherein the base is volatile having a dissociation constant less than 5 10- and the salt is formed from a volatile acid having a dissociation constant less than l0- 6. A composition as specified in claim 1 wherein the pH is about 9.2.

7. A composition as specified in claim 1 wherein said salt is a carbonate.

8. A method for permanently waving hair Without damage to the hair structure which comprises the steps of forming strands of hair into a desired configuration, applying to said strands an aqueous solution containing between about 1% and about 10% of a solution of glyceryl monomercaptan, a base having a dissociation constant less than lO- and a salt formed of said base with an acid, which acid has a dissociation constant less than that of the base, and thereafter fixing said configuration in the treated hair.

9. In the method of claim 8 the step of rinsing said solution from the hair after a selected time of application and before fixing the configuration.

10. The method of claim 8 wherein the pH of the solution is about 9.2.

References Cited in the file of this patent UNITED STATES PATENTS 2,183,894 Pye Dec. 19, 1939 2,352,524 Evans et al June 27, 1944 2,389,755 Baker Nov. 27, 1945 2,506,492 De Mytt May 2, 1950 2,540,980 Beste Feb. 6, 1951 (Other references on following page) 12 FOREIGN PATENTS France July 29, 1947 Great Britain Feb. 24, 1939 France Mar. 20, 1937 Great Britain June 19, 1936 Great Britain Nov. 21, 1949 OTHER REFERENCES Goddard et al.: A Study on Keratin, J. Biol. Chem., 10 vol. 106, 1934, pp. 605-614 (esp. p. 608, 1st two lines). 

1. A PERMANENT WAVING COMPOSITION COMPRISING GLYCERYL MONOMERCAPTAN IN A SOLUTION CONTAINING A BASE HAVING A DISSOCIATION CONSTANT LESS THAN 10-3, AND A SALT OF SAID BASE, SAID SALT BEING FORMED FROM AN ACID HAVING A DISSOCIATION CONSTANT LESS THAN THAT OF SAID BASE, SAID SOLUTION HAVING A PH HIGHER THAN PH 7 AND NOT HIGHER THAN PH 9.5, THE CONCENTRATION OF SAID MERCAPTAN IN TERMS OF WEIGHT PER VOLUME RANGING BETWEEN ABOUT 1% AND ABOUT 10%. 